package com.itheima.common.util;

import java.util.Random;

public class RandomUtil {
 
    /**
     * 获取指定长度随机字符串
     * @param length
     * @return
     */
    public static String random(int length) {
        Random random = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < length; i++) {
            int number = random.nextInt(3);
            long result = 0;
            switch (number) {
            case 0:
                result = Math.round(Math.random() * 25 + 65);
                sb.append(String.valueOf((char) result));
                break;
            case 1:
                result = Math.round(Math.random() * 25 + 97);
                sb.append(String.valueOf((char) result));
                break;
            case 2:
                sb.append(String.valueOf(new Random().nextInt(10)));
                break;
            }
        }
        return sb.toString();
    }

}